1. Field of the Invention
This invention relates to devices for securing electrical connectors to each other and, more particularly, to devices for preventing disconnection of a plug from conventional wall or extension cord sockets.
2. Description of the Prior Art
Electrical devices are commonly powered through a supply cord terminating in an electrical plug having exposed parallel prongs adapted to be inserted into the recesses of a supply socket. Since many of these electrical devices are somewhat portable, forces are often exerted on the electrical supply cord which may disengage the plug from the socket, strain the prongs of the plug, or damage the cord at the point where the cord meets the plug.
Many attempts have been made in the prior art to overcome the above-described problems. U.S. Pat. No. 2,913,719, issued to Martin, discloses a plug coupling in which a tapered liner member surrounds the cord adjacent the plug, and a tapered shell connected to the outlet is slipped over the liner. Forces exerted on the supply cord cause the shell to compress the liner to prevent relative movement between the cord and shell.
U.S. Pat. Nos. 2,461,427 and 2,720,633, issued to Kneebone and Westberg, respectively, disclose devices for maintaining an electrical connection between a plug and an extension cord socket. However, the device of Kneebone does not prevent damage to the plug prongs; and the device of Westberg does not adequately prevent plug and cord separation since the clamp is resilient, which allows the connectors to be separated by a sufficient force.